If you are experiencing no audio, the Windows Audio Service may have been disabled or set to manual. You may also see the messages No Audio Device or There are no active mixer devices available . To fix these messages, enable the Windows Audio Service by following these steps: Click Start , Run , and enter services.msc into the Open field. A services window opens. Scroll down the list of services and find Windows Audio. Right-click Windows Audio and select Properties . Select Automatic from the Startup type dropdown list, and click Start to start the audio service Click OK and test for sound. If sound is now restored, a software program may have disabled Windows Audio or is preventing Windows Audio from automatically starting when Windows opens. If your computer continues to experience no sound after restarting the computer, repeat these steps to re-enable Continue to the next step if you still cannot hear sound after enabling Windows Audio. Step 5: Restoring the original audio driver Files and settings for your sound card may have changed and could be causing a sound problem. Use the HP or Compaq application recovery process to restore the audio driver to their original files and settings. You can find the software program in the start menu under either HP Tools , HP Help & tools , or Compaq , Compaq Tools . For more information, refer to Using Application Recovery (Windows 9x, Me, and XP) . Restart the computer after restoring the audio driver software and test for sound